Holography, Gauge-Gravity Connection and Black Hole Entropy

The issues of holography and possible links with gauge theories in spacetime physics is discussed, in an approach quite distinct from the more restricted AdS-CFT correspondence. A particular notion of holography in the context of black hole thermodynamics is derived (rather than conjectured) from rather elementary considerations, which also leads to a criterion of thermal stability of radiant black holes, without resorting to specific classical metrics. For black holes that obey this criterion, the canonical entropy is expressed in terms of the microcanonical entropy of an Isolated Horizon which is essentially a local generalization of the very global event horizon and is a null inner boundary of spacetime, with marginal outer trapping. It is argued why degrees of freedom on this horizon must be described by a topological gauge theory. Quantizing this boundary theory leads to the microcanonical entropy of the horizon expressed in terms of an infinite series asymptotic in the cross-sectional area, with the leading `area-law' term followed by finite, unambiguously calculable corrections arising from quantum spacetime fluctuations.Comment: 12 Pages Latex, 5 eps figures, based on invited talk given at the PAQFT08 Conference held at Nanyang University, Singapore in November 200

Schwarzschild horizon dynamics and SU(2) Chern-Simons theory

We discuss the effect of different choices in partial gauge fixing of bulk local Lorentz invariance, on the description of the horizon degrees of freedom of a Schwarzschild black hole as an SU(2) Chern-Simons theory with specific sources. A classically equivalent description in terms of an ISO(2) Chern-Simons theory is also discussed. Further, we demonstrate that both these descriptions can be partially gauge fixed to a horizon theory with U(1) local gauge invariance, with the solder form sources being subject to extra constraints in directions orthogonal to an internal vector field left invariant by U(1) transformations. Seemingly disparate approaches on characterization of the horizon theory for the Schwarzschild black hole (as well as spherical Isolated Horizons in general) are thus shown to be equivalent physically.Comment: 22 pages Latex, no figures, version accepted for publication in Physical Review

Design and Development of Sports Intimate Apparel - A Review

It is necessary to evaluate and analyze the brassiere design problems to alleviate theproblems in terms of fit, support, elastics and fastening. With an aim to achieve a perfectbrassiere, designers have a strong drive to develop a super quality brassiere with highperformance and proper usage of components and materials. The encapsulation brassiere wasmore effective than compression brassiere in controlling breast displacement. The mainproblems were shoulder straps digging into the shoulder and shoulder straps slipping off theshoulder. There are several design flaws associated with these sports brassiere which lead todiscomfort, pain and swelling of the breasts. Tightness around the chest may also cause beastsoreness. The straps are often very thin and cut into the shoulders of women. The mosteffective brassiere had a unique inverted-u shape bounded seam over the upper and sideboundaries of the cups with a wide cross-back design. Wicking materials are used in this typeof brassieres to give comfort and breast supporting pads having pad components to giveadequate support. The inner layer consists of silicone material which can increase theadherence capacity due to its high coefficient of friction. This review paper contains detailsabout the design and development of sports brassiere

Charge-monopole versus Gravitational Scattering at Planckian Energies

The amplitude for the scattering of a point magnetic monopole and a point charge, at centre-of-mass energies much larger than the masses of the particles, and in the limit of low momentum transfer, is shown to be proportional to the (integer-valued) monopole strength, assuming the Dirac quantization condition for the monopole-charge system. It is demonstrated that, for small momentum transfer, charge-monopole electromagnetic effects remain comparable to those due to the gravitational interaction between the particles even at Planckian centre-of-mass energies.Comment: 9 pages, revtex, IMSc/93-4

Generalized Hawking-Page Phase Transition

The issue of radiant spherical black holes being in stable thermal equilibrium with their radiation bath is reconsidered. Using a simple equilibrium statistical mechanical analysis incorporating Gaussian thermal fluctuations in a canonical ensemble of isolated horizons, the heat capacity is shown to diverge at a critical value of the classical mass of the isolated horizon, given (in Planckian units) by the {\it microcanonical} entropy calculated using Loop Quantum Gravity. The analysis reproduces the Hawking-Page phase transition discerned for anti-de Sitter black holes and generalizes it in the sense that nowhere is any classical metric made use of.Comment: 9 Pages, Latex with 2 eps figure

Impact of soil moisture and plant population on yield components and yield of maize (Zea mays)

Experiment was conducted with three water levels such as 100, 75 and 50 % with three spacing, viz. normal, narrow and reduced narrow spacing of maize. Reducing the plant spacing, enhanced the plant population per unit area which increases maize yield even under reduced soil moisture level. Individual treatments of normal irrigation practice, narrow plant spacing and its interaction registered better performance of kernel, stover yield and yield attributes

Studies on the blends of n-butylme thacrylate ethyl acrylate copolymers chlorinated rubber as top coat

The copolymers of n-butylmethacrylate-ethylacrylate were blended with chlorinated rubber in solution. The lacquers were formulated based on each blends and their utility as top coats on leather substrates were assessed. It was concluded that the blends resulted out of the above two polymer systems serve as the source for the formulation of top coats on leather substrate

Electromagnetic and Gravitational Scattering at Planckian Energies

The scattering of pointlike particles at very large center of mass energies and fixed low momentum transfers, occurring due to both their electromagnetic and gravitational interactions is re-examined in the particular case when one of the particles carries magnetic charge. At Planckian center-of-mass energies, when gravitational dominance is normally expected, the presence of magnetic charge is shown to produce dramatic modifications to the scattering cross section as well as to the holomorphic structure of the scattering amplitude.Comment: 33 pages, Revtex file, no figs; a footnote and two references adde

Eikonal Particle Scattering and Dilaton Gravity

Approximating light charged point-like particles in terms of (nonextremal) dilatonic black holes is shown to lead to certain pathologies in Planckian scattering in the eikonal approximation, which are traced to the presence of a (naked) curvature singularity in the metric of these black holes. The existence of such pathologies is confirmed by analyzing the problem in an `external metric' formulation where an ultrarelativistic point particle scatters off a dilatonic black hole geometry at large impact parameters. The maladies disappear almost trivially upon imposing the extremal limit. Attempts to derive an effective three dimensional `boundary' field theory in the eikonal limit are stymied by four dimensional (bulk) terms proportional to the light-cone derivatives of the dilaton field, leading to nontrivial mixing of electromagnetic and gravitational effects, in contrast to the case of general relativity. An eikonal scattering amplitude, showing decoupling of these effects, is shown to be derivable by resummation of graviton, dilaton and photon exchange ladder diagrams in a linearized version of the theory, for an asymptotic value of the dilaton field which makes the string coupling constant non-perturbative.Comment: 22 pages, Revte

Universal canonical entropy for gravitating systems

The thermodynamics of general relativistic systems with boundary, obeying a Hamiltonian constraint in the bulk, is argued to be determined solely by the boundary quantum dynamics, and hence by the area spectrum. Assuming, for large area of the boundary, (a) an area spectrum as determined by Non-perturbative Canonical Quantum General Relativity (NCQGR), (b) an energy spectrum that bears a power law relation to the area spectrum, (c) an area law for the leading order microcanonicai entropy, leading thermal fluctuation corrections to the canonical entropy are shown to be logarithmic in area with a universal coefficient. Since the microcanonical entropy also has univeral logarithmic corrections to the area law (from quantum spacetime fluctuations, as found earlier) the canonical entropy then has a universal form including logarithmic corrections to the area law. This form is shown to be independent of the index appearing in assumption (b). The index, however, is crucial in ascertaining the domain of validity of our approach based on thermal equilibrium.Comment: 6 pages revtex, one eps figure; based on talk delivered at the International Conference on Gravitation and Cosmology held at Kochi, India during 5-9 January, 200